The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
An engine combusts an air/fuel mixture to produce drive torque. A richer or leaner air/fuel ratio may be provided by adjusting, for example, position of an intake air control throttle or an amount fuel that is injected into cylinders of the engine during each combustion cycle. During certain conditions a richer air/fuel ratio is desired to provide increased output torque. This can occur based on power enrichment (PE) scheduling.
PE scheduling is generally initiated when an engine is under high load to provide additional torque output. During a PE mode, an engine control system commands a richer than stoichiometric fuel equivalence ratio (FEQR). FEQR refers to a current fuel-to-oxidizer ratio divided by a stoichiometric fuel-to-oxidizer ratio. A stoichiometric FEQR is equal to one (1). The richer FEQR (ex. FEQR >1) increases engine output torque. In airflow based engine control systems, PE scheduling may be based on actual throttle position and air pressure within an intake manifold of an engine.